The disclosure relates to a semiconductor device, and can be applied to, for example, a microcontroller that supplies a power source to an external sensor.
In order to improve complexity of an in-vehicle system, a single wire bus has been proposed. A power source is supplied to a device using a signal line in the single wire bus, and thus a power source circuit for the device is not needed. The device adapted to the single wire bus uses the power source for the device in such a manner that a capacitor is coupled to the signal line through a diode and the voltage of the signal line is charged to the capacitor (for example, US Patent Application Publication No. 2008/0298385).